Custom Audiences

Custom Audience from a customer list is a type of audience you can create made up of your existing customers. You can target ads to the audience you've created on Facebook, Instagram, and Audience Network.

You give us your hashed customer list by uploading it, or by integrating with your CRM with Marketing API. For the upload option in Ads Manager or Power Editor for Custom Audiences, see Help Center, What's a Custom Audience

Build an Audience

As the owner of CRM data and other business data, you will be responsible for creating and managing this data. To create an audience, you will share your data in an encrypted format to maintain privacy. Facebook compares your encrypted data with encrypted data on our side to see if we can add someone to an audience for your ad.

The accepted method for hashing is SHA256. Other hashing mechanisms are not supported.

Facebook compares your data with our encrypted user data. If we find a match, we can add people to your Facebook Ads custom audience and deliver ads to them. A successful return result looks like this:

The num_invalid_entries indicates a number of users that did not match and are not in the custom audience. This number is not exact but represent the number range of users which do not match.

Opting-Out Users

If a person has opted out of being targeted, you must remove the person from all custom audiences containing this person. To do so, you can send us the person and Facebook will delete them from all audiences that you own so that you don't have to remember which audience this person is a part of.

To opt-out a person from audience after they have clicked through to your opt-out URL, make an HTTP DELETE call to